Liquid bulk carrying ship

ABSTRACT

A liquid carrying tanker comprising a plurality of closed individual reservoirs for receiving a liquid, an ejecting piping system for connecting the upper part of each reservoir to an empty space, and an impermeable, elastomeric tailored lining releasably fixed to the inner walls of said reservoirs, the said lining being adapted to separate from the walls of at least one of the reservoirs upon a predetermined minimum external concussive pressure and deformation of the walls of said one reservoir, the lining being adapted to stretch upon said pressure and deformation and force the liquid contained therein to flow through said ejecting piping system and towards said empty space.

ilnited States Patent 1191 clrauglilin et al.

[ LIQUID BULK CARRYING SHIP [22] Filed: June 5, 1972 [21] Appl. No.: 259,426

[ US 1 4L WRL114L91ZZQL 42229193381 161/182, 161/194, 161/203, 161/216 51 int. c1 B63b 25/08 [58] Field 61 Search 114/68, 69, 72, 74 R; 220/63 R, 9 A, 63 A, 85 B; 244/135 B;

293/71 R, 71 P, DIG. 2; 161/203; 117/74,

2,774,704 12/1956 Smith 220/63 R 3,024,941 3/1962 Vandenberg 220/63 R 3,307,512 3/1967 Fell ll4/74 R 3,475,383 10/1969 Stewart 220/63 A 3,588,159 6/1971 Duckett et al. 293/71 R 3,622,035 1l/1971 Suter 220/63 A 3,632,791 l/l972 Rupprecht et al. l6l/203 Primary Examiner-George E. A. Halvosa Assistant Examiner-Edward R. Kazenske Attorney, Agent, or FirmBacon & Thomas [57] ABSTRACT A liquid carrying tanker comprising a plurality of closed individual reservoirs for receiving a liquid, an ejecting piping system for connecting the upper part of each reservoir to an empty space, and an impermeable, elastomeric tailored lining releasably fixed to the inner walls of said reservoirs, the said lining being adapted to separate from the walls of at least one of the reservoirs upon a predetermined minimum external concussive pressure and deformation of the walls of said one reservoir, the lining being adapted to stretch upon said pressure and deformation and force the liquid contained therein to flow through said ejecting piping system and towards said empty space.

8 Claims, 20 Drawing Figures 1 LHQUKD BULK CARRYING SHIP BACKGROUND 1. Field of the Invention The present invention is directed to a liquid bulk carrying ship and more particularly to means for preventing spillage of a fluid in liquid bulk carrying ships in case of collision or structural failure.

2. Description of the Prior Art Liquid bulk vessels, because of physical laws governing free liquid surfaces and surge, are by necessity divided into a number of compartments, reservoirs or cargo carrying tanks. Access between these tanks is restricted to pump lines for loading, discharging, or ballasting, and to steam or electric lines for the activation of heating coils set in the bottom of each tank as necessary. The tanks can be completely closed off, or opened in a direct or articulated manner by automatic or manual valves situated either on deck, or in a central pump room or both. Physical entrance to each tank is made through hatches or through manholes. The tanks are usually centrally vapor vented through the masts, sampson posts and individual vents located on deck. ln the event of marine diasters, in the vast majority of cases, a damaged, stranded, or wrecked tanker looses her pollutant cargo progressively as each cargo tank is fractured as the result of pressures built up by the original fracture.

Immediately following a collision, the fractured tank or tanks, may be flooded in order to maintain the proper relative pressure inside the tank with respect to outside water pressure. If not already stopped, the ship should be stopped in the water, and should only be permitted slow movement when buoyancy checks have been made and fractured tanks securely closed off.

Liquid bulk carriers commonly known as tankers have a complex structure made of steel to provide a triple function, that is, (l) the hull must be watertight to keep the vessel seaworthy; (2) the hull must be strong enough to support the tanker without damage under all reasonable conditions of stress, strain and perils of storms at sea; and (3) it must contain the liquid cargo without spillage. Obviously, if pollution does take place, it is caused by a spillage of the pollutant liquid due to the ship breaking open as a result of stranding, hitting a rock or other underwater obstruction or by being in collision with another vessel.

If one examines the record of naval disasters it is interesting to see from information culled from such publications as Lloyds Casualty Return, that in the last few years, the number of disasters has progressively increased and is approximately as follows:

Merchant ships lost (above 100 tons gross) for all reasons with no separation by type:

1948 2l0,000 gross tons I958 350,000 gross tons 1968 770,000 gross tons 1970 640.000 gross tons Although it would be unreasonable to expect that an unsinkable ship could be designed, it is one of the objects of the present invention to offer a protection in a great number of circumstances in which liquid bulk carriers are damaged. Statistics also indicate that a large quantity of spilled pollutant liquid from tanks are due to minor accidents or leakage from tankers.

. SUMMARY OF THE INVENTION According to the present invention, liquid bulk vessels are provided with a plurality of closed individual reservoirs or tanks, each reservoir is provided with an impermeable elastomeric tailored lining releasably fixed to the inner walls, and this lining is adapted to separate from the walls upon a predetermined minimum external concussive pressure and deformation of the walls of the reservoir. The material used for such a lining is stretched upon the action of the pressure and the deformation, the reduction of volume within this lining forces the liquid contained therein to move outwardly of said tank towards an empty space.

It follows, of course, that if the lining is formed by a bag, the latter must be secured to the walls of the reservoir in such a way as to permit simplicity of fitting and proper security, while at the same time allowing the securing device to part at a precalculated minimum tension since, if the ship suffers a collision and a reservoir is broached by the invasion of the bow of the colliding ship, the resulting shock wave passing through the fluid cargo will tend to rip the bag unless it is permitted to part from the supporting structure and become free to move and be self-supporting. The shock wave is handled so that the displacement of the liquid created by the shock wave is absorbed without equivalent damage to the other side of the ship. The arrangement used in this instance is a piping system leading from each tank to three locations but separated from these locations by rapid acting pressure controlled valves. The three locations in question are l the other reservoir of the ship, (2) a ballast tank; (3) up the mast to a significant height and then directed over board. The third alternative is an emergency measure since it is possible to anticipate an impact of such magnitude that immediate dumping to other tanks or other containing quarters cannot be totally absorbed and one must then recognize that to salvage the majority of the cargo, some of it must be jettisoned.

The use of bags fitted in the reservoirs according to the invention is an advantage in existing structures where these structures are not overly complicated. Such bags are also an advantage in older ships where the structure is becoming rather seriously corroded and where it becomes uneconomic to either replace steel that has approached the minimum corrosion margin or to clean steel that is excessively corroded due to certain cargoes which encourage such an attack or deposit.

Another type of lining to be fixed on the inner walls of the reservoir and which is reversed for new construction or ships that have an excessively complicated internal structure, but are young enough to offer a surface that can be considered as clean, is to utilize a new family of elastomeric liquid chemicals that are capable of being sprayed on. Such spray-on processes may be of three parts, the first of which is a special formulation that provides a parting surface of pre-calculated strength between the steel and the second application of chemical; the second application is a chemical of such characteristics as to provide a reasonably elastic high strength which, in fact, provides the basically required objective of the invention; the third application is the final internal coating which is applied for the sole purpose of offering an impervious chemically resistant surface to the liquid being carried.

The first layer has an adhesion to the surrounding steel which is strong enough only to maintain the position of the membrane or layer under normal operating conditions, but weak enough to part from the structure when presented with strong external concussive forces. The material of the second layer must be strong enough and flexible enough so that it will not rupture or fail under reasonable circumstances, such as the withdrawal of supporting structure, and will stretch sufficiently to allow for deformation or opening of the structure. The third layer which is the internal surface of the lining, should not only be impervious to the passage of the transported liquids but also chemically inert and, therefore, not subject to chemical or corrosive attack.

A rapid release system of the liquid with delivery to other areas of containment for liquids that are rapidly displaced as the result of concussion by an intruding or invading vessel or object is also foreseen.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side view of a bulk liquid vessel with the side partly ripped off for showing the reservoirs,

FIG. 2 is a top plan view of the central portion of the ship as illustrated in FIG. I,

FIG. 3 is A cross-sectional view of a tanker with its side damaged by another ship,

FIG. 4 is a cross-sectional view of the side of a tanker being damaged by a ship,

FIG. 5 is a view similar to FIG. 4 but illustrating an alternative construction of the side of the tanker,

FIG. 6 is a magnified view of the hull of a tanker having a coated lining of elastomers,

FIG. 7 is an enlarged view of a web of the hull illustrated in FIG. 6,

FIG. 8 is a view similar to FIG. 6 illustrating a double hull, the inner hull constituted by an elastic bag fastened to webs connected to the outer hull,

FIGS. 9-13 are side views of various fastenings means for connecting the plastic bag to the outer hull,

FIGS. 14-17 show various means for sealingly con necting a tube through a plate or hull,

FIG. I8 displays a side view of an arrangement for emptying reservoirs of a tanker.

FIG. 19 and 2t) illustrate two orthogonal front views of the bag as shown in FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The bulk liquid vessel or tanker I0 illustrated in FIG. I has a hull l2, a mast Ml and a cabin section 16. The central portion is cut away so as to illustrate the tanks or reservoirs I8-36 located in the hull 12. These reservoirs are adapted to receive a liquid to be transported by the tanker I0. Each of these reservoirs has an outlet pipe I8b-36b and each of these outlet pipes is connected to a main outlet pipe 40. This main outlet pipe 40 is connected to a mast pipe 42.

Each reservoir is also provided with manhole 280-36c as illustrated in FIG. 2, and 50 illustrated in FIG. 3. These manholes are used by the operators to go down the reservoirs when cleaning, repairing or general maintenance is needed.

According to the invention, various types of valves may be selectively used above each reservoir, such as l. Eccentrically balanced two directional butterfly valves, capable of being adjusted to burst open in either direction at a pre-calculated pressure, and also controlled (open or shut) by an external lever, similar to a modification of a Weir'Pacific Monoseal valve.

2. A pair of pressure loaded swing check valves, operating uni-directionally in Siamese Branch pipes. similar to a modification of a Mission Duo-Chek Check Valve.

3. A diaphragm insert arranged for easy replacement, designed to rupture in either direction at a precalculated pressure, to be inserted in the main pipeline branch pipe, accompanied by a parallel by-pass pipe of smaller diameter, fitted with a conventional control valve. This smaller pipe used for filling and emptying purposes.

Each secondary outlet pipe l8b-36b is provided accordingly at a portion above the reservoir, with a diaphragm valve 52, 54 and 56 of which the diaphragm is laterally removable by a sliding mechanism partially illustrated in FIG. 3 by reference number 54d and in FIG. 2 by reference numbers 36d for reservoirs 36 and 36a. These diaphragms 52, 54 and 56 are adapted to close the outlet of each reservoir but upon a predetermined minimum pressure from the liquid in the reser voir will break to let the liquid pass through the outlet pipes I8b-36b and through the main pipe 40. As shown in FIG. 3, the diaphragm 56 is broken to let the liquid flow upwardly. The tanker which is illustrated in FIGS. 1, 2 and 3 is provided with reservoirs I8-36 which are divided by transverse bulk heads 60 and longitudinal bulk heads 62.

As it may be seen from FIG. 3, when the tanker I0 is collided by a ship 100, the side of the reservoir 64 is crushed and its volume is reduced at a speed corresponding to the collision and the size of the ship 100. In order to take up the liquid corresponding to the reduction of volume of the reservoir 64, the liquid moves upwardly through the diaphragm 56 which is broken due to the excessive pressure caused by the liquid and flows into the outlet pipe 50b and through the main outlet pipe 40 (FIG. 2). In order to take up this transfer of volume, at least one reservoir among the reservoirs 18-36 is empty so as to receive the overflow. The main outlet pipe 40 is also connected to a mast pipe 42 so that any surplus which could not be absorbed by the evacuated reservoirs will be projected into the sea. However, the projection of the liquid into the sea is only in case of emergency and intended only to prevent greater spillage of liquid. It is also expected that if some of the reservoirs are not completely filled with liquids, the main outlet pipe 40 may bring the liquid to one of the outlet pipes I8b36b so as to fill them.

When a ship 100 collides with a tanker I0 such as shown in FIG. 3, it may be expected that the shock waves and the deformation of the outer hull of the tanker will break open some reservoirs and that spillage may occur. For this purpose, the present invention also includes an inner hull such as shown in FIGS. 4 and 5.

In FIG. 4, the ship 100 has broken open the outer hull of the tanker I0. However, according to the invention, the inner surface of the outer hull 70 is coated with an elastomeric material which is tailored to the hull 70 and which includes the webs 72. The elastomeric material is represented by reference number 74 which is adapted to separate from the walls of the reservoir, these walls being constituted on the lateral side of the ship by the hull 70 and the webs 72. After the coating 74 has detached from the hull 70 and the webs 72, it is adapted to stretch sufficiently so as to pick up the compression caused by the prow of the ship 100. The coating 74 is also adapted to be impermeable to the liquids located inside the reservoir.

In order to obtain these characteristics from the coating 74, it has been found preferable to have a threelayer coating. The first coating is a primer which has an adhesion to the hull balanced in such a way that the layer will part from the surface rather than break. This is achieved by varying the molecular weight, polarity and degree of cross-linking. The basic polymers which may be used for this primer are vinylchloride-vinyl acetate copolymers, bisphenol A/epichlorhydrin condensates, hexamethylene di-isoyanate adducts, styrene/- butadiene and olefin elastomers, polyvinyl butyral. The peel strength can be varied from psi to over 300 psi. The film thickness of the primer is preferably between 0.002 to 0.008 inch.

The intermediate layer is an elastomeric high solids coating preferably based on long chain polyethers or polyesters cross-linked with di-functional isocyanates. It may also be made of interpolymers of epoxides, acrylics butyl rubber or other rubber like derivatives. These materials cure rapidly and it is possible to tailor make the extension and tensile characteristics. To obtain tensile strengths of the order of 10,000 psi, it would be necessary to reinforce the elastomer with fibers either woven or chopped and sprayed into the coating.

The fibrous and reinforcing materials may include nylon, polyester, fiberglass and glass flakes. The thickness of the intermediate layer is preferably from 0.020 to 0.050 inch depending of the tensile characteristic required. These characteristics vary with the size of the ship, the size of the reservoir, the type of liquid carried and the type of collision which may also be expected.

The final or seal layer provides for the chemical and solvent resistance characteristics. The polymers involved here would be interpolymers of epoxides, urethanes and hydroxyl modified acrylics or a mixture thereof. Also, aromatic isocyanates may be used as cross-linking agents. The film thickness of this layer varies preferably from 0.003 to 0.010 inch.

These layers are expected to be coated by spraying. The copolymers which may be used in this coating may be built from the following monomers and film formers:

Butyl rubber acrylate esters methacrylate esters styrene and it derivatives I12 epoxides polyisocyanates, both aromatic and aliphatic polyesters vinyl monomers e.g., vinyl chloride, vinyl acetate, vinyl alcohol, vinyl acetals maleic acid and anhydride fumaric acid phenoplasts poly-ethers urea/formaldehyde condensates malamine/formaldehyde condensates chlorinated rubber isomerised rubber polyamides polysulphides.

FIG. 6 shows a portion of the contour of a reservoir such as shown in FIG. 4 but in an enlarged scale in which the coating 74 entirely covers the webs 74 and the cross webs 75 and the inner surface of the hull 70 so that when the coating 74 peels off from the webs and the hull, it will form a completely enclosed unit to preserve the liquid contained therein.

FIG. 7 is an enlarged view of a web 72 shown in FIG. 6 having a T-shape, the cutting edges of the two extended arms of the T being covered by a semicylindrical protector 71. These protectors are provided to prevent the elastomers coating from cutting, if too great pressure is exerted over such sharp edges. FIG. 7 also illustrates the primer 73 which will provide the proper adherence between the coating 74 and the metallic web 72.

FIG. 5 illustrates a different embodiment in which a ship 100 has collided against the side of the tanker 10. The latter is constituted by a rigid hull inside of which project web plates 82. A resilient bag 84 is releasably connected to the web plate 82. According to the embodiment shown in FIG. 5, the inner ends of the web plates 82 are provided with a rigid socket 86 and the outer surface of the bag 84 is provided with projections adapted to be secured to the socket 86.

The material used for the bag 84 is the same as the one used for the intermediate and the inner layer of the coating 74 described above concerning FIGS. 4, 6 and 7.

According to the present invention, the bag 84 is constituted by a plurality of elementary units 84a, 84b, 84c as shown in FIGS. 19 and 20. These elementary units are provided with the projections on one side thereof and mounted unassembled inside the hull 80. Subsequently, while in position, these units are sealed to one another in a conventional manner by a worker inside the reservoir.

As it may be seen from FIG. 5, when a ship hits the tanker 10, the outer hull is ripped open. The prow of the ship 100 pushes against the bag 84 and disconnects the projections 84 from the sockets 86. The resiliency and the strength of the bag permits it to change its shape according to the pressure exerted. As explained above, the liquid contained in the reservoir 92 will flow through the outlet pipe located at the top of the reservoir as illustrated in FIG. 3 according to the reduction of volume of the reservoir 92.

FIG. 8 illustrates an enlarged embodiment of a reservoir according to FIG. 5 in which the bag 84 is installed in its position of normal operation. The bag is releasably fixed to the webs 82 by breakable couplings constituted by a socket 86 in which the projection 88 is releasably held.

FIGS. 9-13 illustrate various embodiments of the re leasable couplings used in the embodiment of FIG. 8.

FIG. 9 illustrates one of these couplings in which the bag 84 is held to the web 82 by a pair of brackets 77 and 79. These brackets are L-shaped and engage over one another so that when the sidewall of the bag 84 is tilted sufficiently it will unhook itself from the web 82. The hook 77 is rigidly secured to the web 82 while the hook 79 is permanently fastened to the bag 84.

FIGS. 10 and 11 illustrate another embodiment of the coupling between the bag 84 and the web 82. A pair of plates 86a and 86b are welded to the web 82 and a single plate 88 is permanently fastened to the bag 84. The plate 88 is disposed between the two plates 86a and 86b and held together by a shear pin 89 passing through the plates. The shearing power of the pin 89 is computed according to the desired retention of the bag to the web 82. Another embodiment of a combination of a socket and a projection is illustrated in FIGS. 12 and 13 wherein plates 86c and 86d are outwardly fixed the bag 84 may be located closer to the surface 82 and if this surface is extended substantially over the full surface of the bag 84, it will present or reduce small vibrations exerted by the bag 84.

FIGS. 14-16 illustrate various embodiments for providing an appropriate seal between a pipe and a reservoir through which the pipe passes.

FIG. 14 represents the upper part of a reservoir and an outlet pipe of the type shown in FIG. 3 and which is mounted substantially flush with the inner part of the reservoir 101. The coating 104 which is deposited inside the reservoir ltll follows the inner contour of the pipe 102. The upper edge of the coating 104 which enters the pipe 102 is tightened between the upper edge of the pipe 102'and the lower edge of the pipe 106 to form a seal. With this arrangement, the only opening of the bag formed by the coating 104 will remain aligned with the outlet pipe 102 and attached thereto.

FIGS. I5, 16 and I7 illustrate distinct sealing arrangements between a tube 108 and a pannel 110 which is crossed by the tube 108. In the three cases, a sealing ring is foreseen. According to FIG. 15, a space is left between the pannel I and the tube 108 and a sealing ring 112 extends around the tube 108 from below the surface of the pannel 110 to its upper surface. The sealing ring 112 passes through the space between the pannel 110 and the tube 108.

According to FIG. 16, the pannel 110 tightly surrounds the tube ll08 and is welded thereto. The sealing ring 114 surrounds the tube 108 below the pannel 110.

' A part of the tube 108 is threaded so as to engage a locking nut 116 which is intended to tighten the sealing ring 114. According to FIG. 17, the sealing 114 is substantially identical to the one of FIG. 16 except that no locking nut is contemplated. The sealing rings are contemplated for drain holes, manholes or the like.

In FIG. 18, the bottom of a reservoir is partially illustrated in section and shows a small amount of liquid between the webs 120. Reservoirs in tankers are usually filled and emptied with a large pipe 122 but when the reservoir must be emptied, such large pipe cannot move in between the webs 120 and even if the pipe 122 could be introduced between the webs 120, the process would be very slow. Furthermore, a pipe having a large diameter would not be very effective near the bottom of the reservoir. Accordingly, in a reservoir such as shown in FIGS. 4, 6 and 18, a main stripping pipe 124 is contemplated to which is connected a plurality of branch pipes 126 reaching to the bottom of each alcove or bay between the webs 120. In order to avoid valving or in order to ensure that, when one alcove or bay has been drained, it could then commence sucking air without detriment of the remaining liquid to be remove, the main stripping pipe I24 is of a decending order of diameter. The tapering of the main stripping pipe from one bay to another is calculated in order to ensure that all branch pipes remove liquid from their individual bay at the same rate of speed. Also, if one branch pipe, by some accident, commences sucking air, the volume of air sucked will not be sufficient as to prohibit the continued activity of the remaining branch pipes which are still required to deliver the liquid remaining in their alcoves.

This system of emptying the reservoir is contemplated because contrary to'sorne previous reservoirs, no apertures can be contemplated through the webs due to the coating 121.

We claim: I

l. A liquid carrying tanker comprising a plurality of closed individual reservoirs for receiving and carrying a liquid an ejecting piping system connecting the upper part of each reservoir to an empty space and provided with a rapid acting pressure controlled valve adjacent each said reservoirs, said valve keeping the liquid inside the reservoir from flowing into the ejecting piping system during normal operation, and an impermeable, stretchable, elastomeric lining conforming to and extending throughout the entire inner surface of each reservoir and being releasably secured to the inner walls of said reservoirs, the said lining being secured to said walls by releasable means permitting the same to separate from the walls of any one of the reservoirs upon a predetermined minimum external concussive pressure and deformation of the walls of said one reservoir, the lining being stretched upon said pressure and deformation to decrease the volume within said one reservoir and force the liquid contained therein to open said valve and to flow through said ejecting piping system and towards said empty space.

2. A tanker as recited in claim 1, wherein the said lining is adheringly coated on the walls of each reservoir, the adherence of said lining on the walls of anyone of said reservoirs being adapted to break upon a predetermined minimum pressure and deformation of the walls of said anyone reservoirs.

3. A tanker as recited in claim 1, wherein the lining comprises three superposed layers, a first layer consisting of a primer having a releasable adhesion, a second layer consisting of an elastomeric high solid and a third layer consisting of a protective coating.

4. A tanker as recited in claim 3, wherein the primer is made of a compound selected from the group consisting of vinyl chloride/vinyl acetate copolymers, bisphenol A/epichlorhydrin condensates, hexamethylene di-isoyanate/polyester adducts, styrene/butadiene and olefin elastomers, polyvinyl butyral.

5. A tanker as recited in claim 1, wherein said empty space is a ballast tank, the said ejecting piping system being connected to said ballast tank.

6. A tanker as recited in claim 1, comprising a mast pipe reaching substantially above the reservoirs of the tanker, the said mast pipe being connected to the ejecting piping system.

7. A tanker as recited in claim 1, wherein the lining of each reservoir is made of a plurality of assembled units, sealed together and spaced from the walls of the reservoir and fastening means releasably connecting each unit to said walls.

8. A tanker as recited in claim 7, wherein the fastening means are mechanical couplings adapted to shear or break away from a predetermined minimum pressure. 

1. A liquid carrying tanker comprising a plurality of closed individual reservoirs for receiving and carrying a liquid an ejecting piping system connecting the upper part of each reservoir to an empty space and provided with a rapid acting pressure controlled valve adjacent each said reservoirs, said valve keeping the liquid inside the reservoir from flowing into the ejecting piping system during normal operation, and an impermeable, stretchable, elastomeric lining conforming to and extending throughout the entire inner surface of each reservoir and being releasably secured to the inner walls of said reservoirs, the said lining being secured to said walls by releasable means permitting the same to separate from the walls of any one of the reservoirs upon a predetermined minimum external concussive pressure and deformation of the walls of said one reservoir, the lining being stretched upon said pressure and deformation to decrease the volume within said one reservoir and force the liquid contained therein to open said valve and to flow through said ejecting piping system and towards said empty space.
 2. A tanker as recited in claim 1, wherein the said lining is adheringly coated on the walls of each reservoir, the adherence of said lining on the walls of anyone of said reservoirs being adapted to break upon a predetermined minimum pressure and deformation of the walls of said anyone reservoirs.
 3. A tanker as recited in claim 1, wherein the lining comprises three superposed layers, a first layer consisting of a primer having a releasable adhesion, a second layer consisting of an elastomeric high solid and a third layer consisting of a protective coating.
 4. A tanker as recited in claim 3, wherein the primer is made of a compound selected from the group consisting of vinyl chloride/vinyl acetate copolymers, bisphenol A/epichlorhydrin condensates, hexamethylene di-isoyanate/polyester adducts, styrene/butadiene and olefin elastomers, polyvinyl butyral.
 5. A tanker as recited in claim 1, wherein said empty space is a ballast tank, the said ejecting piping system being connected to said ballast tank.
 6. A tAnker as recited in claim 1, comprising a mast pipe reaching substantially above the reservoirs of the tanker, the said mast pipe being connected to the ejecting piping system.
 7. A tanker as recited in claim 1, wherein the lining of each reservoir is made of a plurality of assembled units, sealed together and spaced from the walls of the reservoir and fastening means releasably connecting each unit to said walls.
 8. A tanker as recited in claim 7, wherein the fastening means are mechanical couplings adapted to shear or break away from a predetermined minimum pressure. 